wheel steering

[Olli Väänänen]

In the plans of Tiki 31 it is suggested that the steering would be arranged with a "whipstaff" or a sort of  tiller bar replica, connected to tiller bars with system of cables. I wanted to use a steering wheel. I figured it should work with the same sort of cable-and-block system described in the plans. Well, it did not. When turning the wheel clockwise the cable pulls the starboard tiller bar the way it should. But because the tiller bars are curved, the port tiller turns somewhat less, and soon the cable to the port tiller is goes slack.

How have you arranged the wheel steering? Are the cables coming from the wheel attached to one tiller bar only, having the connecting rod turn the other tiller. Have you added some sort of a segment? Or have you connected the cables coming from the wheel to both tiller bars? In that case how have you been able to keep both cables taut even when one tiller turns more than the other?

[Olli Väänänen]

Oops! For some strange reason I have mailed this post twice. I do not mind if the moderator deletes one of the two before both of them are replied!

[Olli Väänänen]

Pardon my English: when I said "segment", I meant "quadrant".

[Axel]

I can take a picture of the plans sheet of the Tiki 38 which has wheel steering if that will help?

[Olli Väänänen]

Please do! I'd really like to see it!

Axel said:

I can take a picture of the plans sheet of the Tiki 38 which has wheel steering if that will help?

[Axel]

I don't have it at home Olli but will get them for you tomorrow. It should make the proper layout pretty clear. 

[Olli Väänänen]

Great, Axel,  I'm really looking forward to see the layout!

[Axel]

Here you go Olli, hope this helps.

20181005_185240.jpg

[Olli Väänänen]

Thank you, I really do appreciate this (I've been checking my e-mail every few hours in anticipation of your message!). I have been thinking of attaching the ropes to the tiller connection bar, too. But my problem is that in my present wheel arrangement the length of the rope the wheel gives (and takes) is too short, as the tiller connection bar travels quite a long distance. I probably will have to make changes to my wheel arrangement. Do you think you still could scan the sheet "centre deck structural designs", please. This might give some useful ideas, too!

[Olli Väänänen]

One more thing: what would the maximum rudder angle be? I realised that if the rudder is turned 35 degrees, the tiller connection bar nearly touches the rear deck, and the tiller protrudes very far outside the hull. Actually the tiller hits the wall of the shed where I am building, so I can't turn the rudder that far at the moment! 

[Axel]

Olli,

Although they reference the plans sheet, I dot think it shows much of the rudder detail. But I will look at it again to be sure. 

On the 38 the steering line runs around a drum with several turns for friction. The drum is connected directly to the wheel. The diameter is roughly 100cm.  A larger drum will provide more travel per rotation of the wheel. I can send you the detail pictures of the actual drum arrangement, I can't help you with maximum rudder angle or other information as my boat is apart for moving.

As for the excursion of the tillers, I plan to cut my tillers just inboard of the attachment point for the tiller bar once it's all together to minimize the tiller's travel across the deck. The ends of the tillers don't do anything as far as I can see. That may help solve the problem of the tiller sweep and deck contact.

Hopefully someone with a completed boat can step in to answer the other questions. 

[Olli Väänänen]

Actually, I did some measuring again, and realised that 35 degrees does not make the tiller go that far over the side after all!
Now I measured the travel of the tiller bar, and I figured it would be 180 cm (six feet) from one extreme to the other. If the drum diameter would be 100 mm (4 inches), then one turn of the wheel would give 31,4 cm rope. For 180 cm the wheel would need to turn nearly six full turns. How many turns do you think your wheel would need to swing the rudders from one extreme to the other? With a 5 inch drum it would take 4,5 turns of the wheel (providing the tiller bar movement is 6 feet),

[Axel]

Olli, there is no more useful detail on the 'centre deck' sheet.